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Topic: TBM-700 N731CA crash outside of MMU (Read 85487 times)

Flight was Teterboro to Atlanta and it went down this morning around 10:05L just to the SW of MMU on I-287 in NJ.

This sound clip was created with archives from KEWR New York Departure just after the aircraft's departure from TEB around 09:50L and then the handover to NY Approach Liberty West/South. The TEB tower feed was inop and there is no feed covered for the NY Center freq this aircraft was communicating with at the time of the crash.

Also included are communications between NY Appch (Liberty West/South) and other aircraft around the time of the crash, advising of moderate to extreme rime and mixed icing between 13,000 and FL180.

Using http://www4.passur.com/ewr.html, make the time Dec 20, 2011 10:03am. Set zoom to 20mi and click "Start". Click on the aircraft near Morristown (top left of radar screen)... It's initially a helicopter but then changes to the N731CA aircraft. Notice the altitude go from 18,000 to it's disappearance in about 60 seconds.

Based on the ATC recordings, reports of severe/extreme icing throughout the area within this aircraft's climb altitudes, and the rapid decent at the time of crash... seems plausible this crash could have been icing-related. Any thoughts?

Very unfortunate, regardless. But hopefully we (pilots) can all learn something from this incident.

Is that rate of decent even plausible? I wonder if the transponder or altimeter was wrong. From 18,000 feet to ground in 1 minute is 180 miles per hour straight down...it seems like there should be some horizontal component to the movement. Even AF447 was only falling at 10,000 feet per minute, while keeping around 60 knots forward motion, if I remember right.

I definitely think ice might have had something to do with it. Although I understand the TBM-700 is certified for all IFR flight conditions, and is equipped with de-icing boots. Perhaps these boots were never used, and the forces on the wing became too much during the rapid/ uncontrolled descent, and broke one of them off?

Here is a PIREP that reported moderate - severe icing nearby, about 40 mins later at a close altitude:

Remember, boots are not foolproof. Icing can overwhelm the boots and create a 'cavern' effect, creating a void under the ice for the boot to expand with no effect on the ice buildup (not sure how to explain it a little clearer). With the reports of severe icing and airliners mentioning issues fending off the ice, I'm not sure the TBM with just boots could handle that type of encounter.

Is that rate of decent even plausible? I wonder if the transponder or altimeter was wrong. From 18,000 feet to ground in 1 minute is 180 miles per hour straight down...it seems like there should be some horizontal component to the movement. Even AF447 was only falling at 10,000 feet per minute, while keeping around 60 knots forward motion, if I remember right.

Yes. Reports are he lost a wing due to the stresses on the airframe. RIP to that family and their friend.

I currently fly 2 TBM700s and have been in icing conditions on multiple occasions without any complications. The boot system on these aircraft have cycles. There are 3 different boot segments on the wings and one on the tail. The inboard section of the wing and the tail operate for 7 seconds. After this cycle the middle and outboard operate for 7 seconds. Then there is a cycle of 53 seconds that the boots do not operate. There is no way to speed up this cycle. This is the one downfall of this aircraft. Due to this operation cycle, I try to avoid any areas with pireps of moderate ice if possible.

Listing to the audio clip I was reminded of a few things. It's always good to know your abilities as a pilot and the abilities / limitations of the aircraft your flying. When a pilot is over confident in their abilities, and /or over confident in the abilities of the aircraft they are flying, that is usually when bad things happen. It's very hard at this point to say what caused the accident as sometimes many factors can play a role. But given the weather conditions, it's easy to speculate or focus on ice. Having experience in a variety of single and multi-engine aircraft, but no time in the TBM-700 I can only speak in general and not specific to this accident. (Please note, I am not an expert and I feel we are always learning no matter how much experience we have in flying) De-ice boots can be quickly overwhelmed in moderate to severe icing, as well as a single engine turbo prop can be quickly overwhelmed too. When the boots are turned on too early, instead of the ice breaking away, it can form a barrier along the outer limits of the boot extension (as mentioned in a post above). At that point the boots become useless as the ice has caused a cavity for the boots to expand, contract, and never breaking the ice away. When an aircraft tries to climb too aggressively through ice, a reverse horse shoe effect can form along the leading edge of the wing, looking like: )C. ")" -being the shape of ice buildup and "C" -being the leading edge of the wing. Props can be overwhelmed by ice which can reduce the amount of thrust. Ice can make the prop off balance causing vibration and even throwing ice, which can be alarming to say the least. Many de-ice systems in light aircraft are designed to help in the event of an unexpected encounter with ice, buying time to help get out of a dangerous situation. From a human factors perspective, ice buildup can become very stressful and distracting. A white knuckle grip on the controls and looking back at the wings can cause sudden pitching up or banking in a situation where the aircraft is already struggling with performance, in icing, making a dangerous situation deadly. An auto pilot can trim an aircraft to unsafe attitude or power setting while trying to do what is programed in an attempt to overcome the adverse conditions that icing can cause. Fuel tank vents can get iced over causing fuel starvation. Pitot tubes and / or static ports anti ice system can become overwhelmed and in some situations we can forget to turn them on if it’s not done automatically by an ice detection system. Sometimes anti ice or de-ice systems fail which can contribute to an already bad situation.

As for forward movement, if an aircraft goes into a spin that develops into a flat spin, usually there is very little forward movement.

I am not trying to play arm chair quarterback nor am I trying to judge the decision making of the pilot at the controls (as I know nothing about his experience and we have very little information about the accident to go on). It's very sad when a fatal accident happens and my thoughts go out to the victims and their families. When an accident occurs in the industry it's best to let the investigators do their job and we can all learn from the findings. But in the preliminary stages it's best to brush up on our knowledge about the possible factors (NASA has done interesting studies on icing and the FAA has publications) and have discussions in forums such as this to get different perspectives, share experiences and learn from each other. An accident always reminds me that they can happen and it makes me take a second look at the calculated risks that I take. This time of year we need to remind ourselves that weather is not kind and it’s not forgiving. Weather is indifferent and I try to take a realistic approach when going up into the elements.

The remarkable thing is how little time transpired between entering IMC and loss of control…4 to 5 minutes max? Wow! A little frightening to think that, even at gross weight, an aircraft of this stature could encounter so much ice that it becomes unflyable in such a short period of time. Flightaware provides the data: http://flightaware.com/live/flight/N731CA/history/20111220/1400Z/KTEB/KPDK/tracklogBetween 13,900 (start of IMC?) and 17,400 the airspeed and rate of climb falls off pretty quickly. Unless there was a reduction in power, these data seem consistent with increasing drag associated with ice. The idiosyncrasies of the deicing boot cycles on the TBM700 mentioned by Wilky10 are noteworthy. I think the strategy and mindset of how you approach the ice is critical. Do you assume you won’t have a problem and plan to react if you do? Or do you assume you will have a problem and don’t react if the problem doesn’t materialize? There is a critical distinction between these two mindsets. One puts you ahead of the plane the other can put you behind the airplane at a time where behind is really bad.An example….do you fly an ILS with the mindset of “I am going to miss “or I am going to get in? I used to assume the latter. I hadn’t missed an actual approach in years…why would this time be any different? So flying a ILS into IND I had it LOCKED into my mind that I was getting in. Yeah, I briefed the missed approach instructions but my MIND had no intention of missing. Well turns out there was no runway environment in sight at the DH. My first reaction was WTF? The second was to be somewhat insulted (silly as it sounds) and my third reaction was to pitch up, power up at which point I looked down to see what the missed instructions really said. It was a disorienting experience trying to make a full power climbing turn while rereading the instructions I has read less than 5 minutes prior. I didn’t catch up to the aircraft until I was finally reestablished on the ILS. Beat myself up pretty bad over that experience and never forgot it. Every approach I make today I plan on missing. If I break out prior to the MAP/DH I take it as a positive “surprise”. Judging by his words to the controller the pilot of 700CA certainly didn’t anticipate a problem. He even used the words “it will be no problem for us”. And why would it be? Probably seen ice dozens of times and it was never a problem. So the transition from “it won’t be a problem” to “holy crap I am in serious trouble” took less than 5 minutes. Could you get your head wrapped around that swing in reality in a seamless fashion? Would you have the discipline to recognize how bad it would become so quickly and initiate an emergency descent in NY airspace without hesitation? Seems like a pretty tall order. If you agree, plan for an escape no more than 60 seconds after entering IMC when moderate to severe is reported. If you get surprised because it is manageable….it will be a surprise you can live with. It may turn out that that ice had nothing to do with this tragic event or that there were other factors like an out of envelope or overweight aircraft or a systems failure. Regardless, assuming the worst vs. expecting the best is worth considering.

The remarkable thing is how little time transpired between entering IMC and loss of control…4 to 5 minutes max? Wow! A little frightening to think that, even at gross weight, an aircraft of this stature could encounter so much ice that it becomes unflyable in such a short period of time. Flightaware provides the data: http://flightaware.com/live/flight/N731CA/history/20111220/1400Z/KTEB/KPDK/tracklogBetween 13,900 (start of IMC?) and 17,400 the airspeed and rate of climb falls off pretty quickly. Unless there was a reduction in power, these data seem consistent with increasing drag associated with ice. The idiosyncrasies of the deicing boot cycles on the TBM700 mentioned by Wilky10 are noteworthy. I think the strategy and mindset of how you approach the ice is critical. Do you assume you won’t have a problem and plan to react if you do? Or do you assume you will have a problem and don’t react if the problem doesn’t materialize? There is a critical distinction between these two mindsets. One puts you ahead of the plane the other can put you behind the airplane at a time where behind is really bad.An example….do you fly an ILS with the mindset of “I am going to miss “or I am going to get in? I used to assume the latter. I hadn’t missed an actual approach in years…why would this time be any different? So flying a ILS into IND I had it LOCKED into my mind that I was getting in. Yeah, I briefed the missed approach instructions but my MIND had no intention of missing. Well turns out there was no runway environment in sight at the DH. My first reaction was WTF? The second was to be somewhat insulted (silly as it sounds) and my third reaction was to pitch up, power up at which point I looked down to see what the missed instructions really said. It was a disorienting experience trying to make a full power climbing turn while rereading the instructions I has read less than 5 minutes prior. I didn’t catch up to the aircraft until I was finally reestablished on the ILS. Beat myself up pretty bad over that experience and never forgot it. Every approach I make today I plan on missing. If I break out prior to the MAP/DH I take it as a positive “surprise”. Judging by his words to the controller the pilot of 700CA certainly didn’t anticipate a problem. He even used the words “it will be no problem for us”. And why would it be? Probably seen ice dozens of times and it was never a problem. So the transition from “it won’t be a problem” to “holy crap I am in serious trouble” took less than 5 minutes. Could you get your head wrapped around that swing in reality in a seamless fashion? Would you have the discipline to recognize how bad it would become so quickly and initiate an emergency descent in NY airspace without hesitation? Seems like a pretty tall order. If you agree, plan for an escape no more than 60 seconds after entering IMC when moderate to severe is reported. If you get surprised because it is manageable….it will be a surprise you can live with. It may turn out that that ice had nothing to do with this tragic event or that there were other factors like an out of envelope or overweight aircraft or a systems failure. Regardless, assuming the worst vs. expecting the best is worth considering.

^^^^^ Quite possibly the best story/reply/advice I've read online.

The "beat myself up pretty bad" hits home. The road to where we are at in our professional pilot/controller careers is littered with these moments. (lord knows I've had my share). The feeling of invincibility comes from doing the same thing over and over and not getting bit.

Remember, boots are not foolproof. Icing can overwhelm the boots and create a 'cavern' effect, creating a void under the ice for the boot to expand with no effect on the ice buildup (not sure how to explain it a little clearer). With the reports of severe icing and airliners mentioning issues fending off the ice, I'm not sure the TBM with just boots could handle that type of encounter.

Ice Bridging does not exist in modern boots systems and they are not susceptible to run back according to the manufacturers. However Ice accretion rates should be watched carefully. When Airliners are calling sever ice you better avoid the area...

Just an observation about the 2nd recording of the response...is it me or does it seem like the news choppers are like vultures descending on some prey? I understand the need for the press to get the story, it just seemed a bit unsettling knowing 5 people had just died and the news choppers are racing to get the first video of it. Oh well, YMMV. RIP to those lost.

Severe icing = rapid ice accretion, (less than 5 minutes) partial loss of lift, increased drag, causing entry into the back side of the power curve, loss of roll control and resultant stall-spin.Been there, done that.Recovery? Nose down (way, way down), throttle(s) back, controls neutral, then hopefully get to an OAT of 34F or higher and wait until the ice sheds enough to get full contol again.

I am not familiar with the TBM 700 but in addition to the icing issue another factor the NTSB is sure to consider is the loading of the aircraft. With five passengers, a dog, luggage, possible Christmas presents and the fuel on board for the trip, the permissible weight and balance limitations may have been exceeded.

I am ATC and it still amazes me how many pilots listen to the weather warnings and still choose to fly into the affected area. We shake our heads when we see it. It happens so often. I dont understand it. When you fly there are risks. When you fly in IFR there are greater risks. When you put passengers on board wouldnt you want to reduce the risks as much as possible? And when the passengers are children or your family wouldnt you want to even further reduce the risks?

I was once working a student pilot on his check ride. They departed and immediately their radio went bad. Not totally unusable but still bad. I informed him. He chose to continue his flight. And of course they returned nordo a few hours later. We had to put military jets in holding to accommodate his nordo landing. When I spoke to him over the phone he said he knew the radio was bad but they decided to 'go ahead and risk it'.

Now isnt flying risky enough as it is? Why further compound that by flying in controlled airspace with a known bad radio? Especially when the option to return to the airport, spend another half hour preflighting another flight school aircraft and then go off on the flight as intended with less risks? In addition to more risk for yourself you are putting nearby aircraft at risk too by flying in controlled airspace with no communication with the tower.

This is what we dont understand. If youre going to play russian roulette with yourself thats one thing. But dont do it with passengers or other nearby aircraft.

Remember, boots are not foolproof. Icing can overwhelm the boots and create a 'cavern' effect, creating a void under the ice for the boot to expand with no effect on the ice buildup (not sure how to explain it a little clearer). With the reports of severe icing and airliners mentioning issues fending off the ice, I'm not sure the TBM with just boots could handle that type of encounter.

As a TBM pilot, I can tell you that this aircraft should have been able handled it. If I am not mistake here, they were talking about light to moderate icing conditions. VampyreGTX your explanation is correct. This will occur if the boots are activated too early. We don't know when the Pilot decided to activate the deicing boots. Never the less, he should have had his prop deice on and maintain a proper air speed (cockpit management) regardless of the ice. The climb is secondary.

The boots on a TBM work as follows, the inboard come on and cycle for 7 seconds, then the same with the outboard. There is a 53 second or so delay before they are activated again.

Did the Pilot put the boots on too early..? Was his climb too steep and the ice build up was so rapid..? You gotta remember the TBM 700 is a very well built aircraft. For the TBM to break up in flight, one would have to think the speed was in the range of 500+ mph. That's just my two cents.

I would be hard press to see if there was something mechanically wrong with the aircraft.